3-Descyano Febuxostat Ethyl Ester is an impurity of Febuxostat (F229000), a xanthine oxidase/xanthine dehydrogenase inhibitor. Used for treatment of hyperuricemia and chronic gout. 40-120 mg/day febuxostat was proven effective in lowering serum urate levels when administered to manage hyperuricemia in patients with gout.